Tubular silicon members advantageously formed by extrusion from a silicon melt or by fixing together silicon staves in a barrel shape. A silicon-based wafer support tower is particularly useful for batch-mode thermal chemical vapor deposition and other high-temperature processes, especially reflow of silicate glass at above 1200.degree. C. The surfaces of the silicon tower are bead blasted to introduce sub-surface damage, which produces pits and cracks in the surface, which anchor subsequently deposited layer of, for example, silicon nitride, thereby inhibiting peeling of the nitride film. Wafer support portions of the tower are preferably composed of virgin polysilicon. The invention can be applied to other silicon parts in a deposition or other substrate processing reactor, such as tubular sleeves and reactor walls. The tower parts are preferably pre-coated with silicon nitride or polysilicon prior to chemical vapor deposition of these materials, or with silicon nitride prior to reflow of silica.